Archaeology, Historic Preservation, and the Blue Marble

As noted in the MPDF overview, “the full flowering of distinctive agricultural regions in Pennsylvania occurred only in the mid-19thcentury” (McMurry 2012a: 7) and that “the widespread transition to a relatively specialized monocrop or single-product system did not really take hold until after the Second World War in Pennsylvania” (p. 4). Fortunately, this century is well documented in maps, first with county atlases in the 19thcentury, followed by early USGS 15 minute and 7.5 minute topographic maps beginning at the end of the 19thcentury and early 20thcentury, and followed by rather detailed and frequent Department of Highways Type 10 maps beginning in the early 20thcentury and continuing today. It should be axiomatic that earlier roads, and early, improved roads are indicators of principal roadways. Invariably, investments in roads follows need, particularly when through local funding. The dichotomy between earthen and improved roads, whether they are concrete, brick, macadamized, and even bituminous macadamized over chipped stone, can speak to whether the local communities considered any individual road important, or principal. Furthermore, if the history of the Landscape is well known and the peak development of specific agricultural system is marked, then roads improved after that date might not be principal, even if they are within the period of significance.

The upshot of this mapping exercise is that bridge crossings on principal roadways within the Landscape can be identified. With a reasonable history of the Landscape, principal roadways to market can also be identified, and with them, the associated bridge crossings. Crossings on principal roadways defined for the period of significance that still retain the integrity of location would be considered contributing,

Substructure

It is anticipated that the types of abutments and/or piers that might be found within rural areas and Landscapes would be stone of local origin, stone quarried from outside the Landscape, or concrete. Stone of local origin, with vernacular construction techniques should be readily obvious on inspection and inspection of nearby stone buildings and structures. Provided there are no significant later modifications that would substantially diminish the integrity of the substructures (from a NR perspective), then we should assume the substructure would be contributing to the Landscape. For concrete material or quarried stone from outside the Landscape, unless there are local design elements imposed, it would be reasonable to argue the substructure would not be contributing as it would not reflect the local workmanship, methods of construction, materials, stylistic influences, and vernacular forms.

Superstructure

As with the superstructure, the material of construction could be local or exotic. The design could also be vernacular or state-standard. Again, the test of the superstructure would be whether the materials and construction reflect the local workmanship, methods of construction, materials, stylistic influences, and vernacular forms. In most instances this would exclude superstructures undertaken by the Department of Highways after WWI (possibly earlier) that followed a state-standard design. The exception to this “rule” would be where a local authority within the Landscape authorized a locally funded and undertaken road and bridge program to improve movement of goods to market that positively relates to the evolutionary trajectory of the farm system in that region.

Practical Issues for the Transportation Historic Preservationist

How Do we Know We are in a Rural Historic Landscape?

More often than not, the transportation historic preservation specialist is working from a project perspective rather than a resource perspective. It’s the nature of the game. So what happens when the professional drives into the middle of a rural valley, passing farms, a grange, a cemetery, a Walmart, and a housing development along the way? Reaching the bridge project, the professional does a 360 and sees all of the above within view. Is the project in a rural historic landscape or not? And is the bridge contributing to that rural historic landscape, if present?

In a number of instances, the consideration of a bridge as contributing/non-contributing is taken within a fully evaluated Landscape. However, this may be the exception rather than the rule. In the short term, some shorthand may need to be developed to reflect a minimum level of work to ascertain whether a Landscape is likely or not. Use of the MPDF will be helpful in that regard. As suggested by the Pa SHPO, use of historic aerial mapping to determine levels of intrusion and loss of integrity may be one approach, but one that lacks an adequate historic context.

The longer-range solution might be to take all bridge projects on the Long Range Transportation Program and look for concentrations that may be in potential Landscapes; then prioritize those potential Landscapes for evaluation based on the number of upcoming projects. Field views would augment research, with an on-the ground evaluation in the vicinity of the bridge project. This way more bridges projects can be evaluated with less work. Ultimately, a statewide effort along the lines of the Agricultural Context may be needed to assess potential rural historic districts statewide in some systematic manner.

Possible Tools

The above analysis leaves open the possibilities for numerous bridges in rural agricultural regions that might now be considered contributing to a rural historic landscape. If a DOT were to treat these individually, then this could become a major impediment to a state’s bridge program. Certainly in Pennsylvania, and I suspect in other states as well, the largest expansion of bridge building was in the first half of the 20thcentury. Many of these bridges, which would be standard design concrete stringer bridges of modest length, would have reached their use life and in many cases would not be suitable candidates for rehabilitation, certainly not to SOI standards. Rather than treating Section 106 (and 4f) on a case by case basis, this class of action would be a good candidate for a programmatic approach. To that end, I am adding a link to a sample programmatic agreement for bridges in rural historic landscapes.

For DOT’s, Section 106 is only part of the equation. There is also Section 4f. And if you don’t normally deal with 4f, I would strongly urge that you stop reading now and find something more useful for your time. For those of you who are involved with 4f, there is a potential glitch in the application of the Nationwide Programmatic 4f for Historic Bridges. When the project does not use any historic resource other than the bridge itself and the bridge does contribute to a historic district, then the current Nationwide PA for Historic Bridges is the right tool for the right job. However, if the project requires any right of way from any portion of the rural historic district/landscape that is contributing to the District as well as the bridge itself, then depending on which FHWA division you are in, you may be in a bind. Because the Nationwide PA for Historic Bridges only covers the bridge and not other contributing properties, you might find yourself completing an individual 4f for the project, much more work. Some FHWA Divisions have work arounds and avoid this issue, but if yours does not, then I am providing a sample text for a state-level programmatic 4f to cover the situation. I hope you never need to use it.

Please note the language in both programmatic agreements are as generic as I could manage; however, if you do plan to use them, I would highly recommend that you run the language by both your FHWA division and your own lawyers, even before you bring this to the SHPO for further discussion.

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Ira Beckerman

I am recently retired from a 30+ year career in transportation, working mainly in historic preservation. My background is in North American Archaeology, with a PhD from Penn State University, and a special interest in cultural ecology. While much of this blog will be on archaeology and historic preservation, we will necessarily drift into the larger public square of environment and sustainability.
P.S. - That wonderful bow string truss bridge in the header is the Messerall Road Bridge over Pine Creek, in Crawford County, Pennsylvania. Someday, I hope PennDOT will find it a good home.